Seal/foam attic staircase opening

Hello everyone,

we are currently having a KFW40 single-family house built. Recently, a branded attic ladder was installed.

We have a cold roof, so the vapor barrier is located in the upper floor with the following structure from bottom to top:
- Gypsum board
- Counter batten
- Vapor barrier
- 280 WLG 035 insulation between the rafters
- Cold attic

The ladder already has an installed "insulation cushion" to ensure airtight installation. Therefore, the vapor barrier is not glued to the frame of the ladder or similar.
The installation was carried out as follows:


We are now wondering whether the gap/cutout should still be foamed or sealed somehow? According to the site manager, only the cover panel will be placed here and that’s it. However, warm air can permanently rise between the gypsum board and vapor barrier like this. I already think this should technically not be a problem, but would it still be advisable to seal it, for example, with PU foam and then cover it with the panel?



Thank you very much and best regards